Metal finishing Q&As since 1989
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Use of Stainless Steel jigs to cut out stripping after galvanizing
February 25, 2009
Thanks for the great site, been able to have our kettle a few weeks away from operational mainly through info found here. Been asked to galvanize small components 100-500 g each that used to be centrifuged. The client not happy wiht the quality so we will be doing them on jigs.
Question: Is it possible to manufacture the jigs using stainless steel, thus not get them galvanised and so not needing to strip each time after use. Read that SS 400 can not be galvanized can it be used for jigs?
Any other ideas of how to cut down on stripping?
Kind regards
employee/owner - Pietermaritzburg, South Africa
February 27, 2009
Sir:
Most stainless steels are attacked by hot zinc and become embrittled. Even when the racks, jigs look good they can then suddenly break.
Haynes International alloy 556 has been used many, many years for spin baskets with excellent success.
Regards,
Galvanizing Consultant - Hot Springs, South Dakota, USA
First of two simultaneous responses -- February 28, 2009
Titanium has been successfully used for jigging without stripping.
Stainless is not a good idea. As mentioned already it suffers from HCl, but also has lower tensile strengths than mild steel typically.
Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK
Second of two simultaneous responses -- March 2, 2009
Thank You. Decided that it would be far to costly and difficult to make the jigs from such specialized steel. Will it be OK to use quality mild steel and just stripping them after use. Concerned about keeping the both the flux and zinc as clean as possible. Worried about what effect constant reuse of jigs will have.
Thanks
Carl
- Pietermaritzburg
March 9, 2009
Mild steel can be used for hooks, jigs, etc.
But it has a fixed and short life. You need to have some form of visual inspection at frequent and regular intervals, perhaps about monthly, not less than 6 months, but dependent on use (24/7?).
Acid will attack, as will zinc. Both reduce the dimensions of the hook/jig, reducing its strength.
If you can, use very low Silicon steel.
Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK
Dear Sir,
This has reference to the above. Sir, I need some help from you. Could you please send me some images / design showing me how to use Hooks for jigging purpose in hot dip galvanizing instead of GI Wires.
Awaiting your reply.
Regards,
JAINARAYAN Singh
Production Department - United Arab Emirates
September 15, 2011
September 16, 2011
I don't think there's any such thing as a standard jig in galvanizing. It very much depends on the product being galvanized.
Wire is the most versatile, as multiple strands can be used to increase weight capacity, and they can be used on almost any fabrication.
To suspend the wire its common to have a large frame, about the same size as the surface of the kettle, from which the wires are suspended.
Hooks could also be suspended from the same jig, but hooks are more limited in what they can carry.
What product do you galvanize?
Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK
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